Alternative insight to understand the Reynolds number effects in vortex-induced vibration

Abstract Vortex-induced vibration (VIV) has been extensively studied for its significant role in the fatigue of marine structures subjected to excitations induced by vortex shedding. As one of the sub-topics, the Reynolds number (Re) effects on responses neglected by older studies have been verified as non-negligible by more recent studies. In the traditional plot of normalized response amplitude (A*-U*), with some exceptions, the reduced velocity (U*) is varied by changing the velocity of incoming flow, therefore the Reynolds number varies simultaneously. In the present article, a series of experiments are conducted with the variation of cylinder diameter, structural stiffness, and mass ratio, respectively, under the condition of subcritical Reynolds number regime and low mass-damping. Here, a non-dimensional parameter alfa (α ≡ Re/U*) is introduced to relate the responses from experiments at different dimensions, making it feasible to obtain an overall view of responses. In addition to recognizing the Re effects, the influences of the mass ratio are also observed with consideration of the Re effects. Furthermore, a rough response surface of VIV is drawn out initially based on the present experimental results and those from several publications, especially at high Re regime. This new proposed response surface seems to lead to an improvement to the application in engineering.